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Flinders Commonwealth Marine Reserve - Shelf Backscatter Data

Abstract

This resource contains multibeam sonar backscatter data for the continental shelf area of Flinders Commonwealth Marine Reserve,
northeast Tasmania. Multibeam data were collected by Geoscience Australia and University of Tasmania in May 2011 (survey GA0331)
and June-July 2012 (survey GA0337) on RV Challenger. The survey used a Kongsberg EM3002 300 kHz multibeam sonar system mounted
in single head configuration to broadly classify the seabed into hard (bedrock reef), soft (sedimentary) and mixed substrate
types at select locations across the shelf. The 2011 survey involved reconnaissance mapping along a series of cross-shelf
transects, covering a total of 767 line km. For the 2012 survey, multibeam data (bathymetry and backscatter) were collected
at 40 pre-determined stations, each covering an area approximately 200 x 200 m. The location of stations was selected using
a Generalised Random Tessellation Stratified (GRTS) sampling design that ensured an even spatial distribution of sites. Multibeam
data was also collected along transits between GRTS stations (410 line km) and across a 30 km2 area of the outer shelf, incorporating
areas of low profile reef, sandy shelf and three shelf-incising canyon heads. Backscatter data are gridded to 2 m spatial
resolution. The 2012 survey also included seabed observations at the 40 GRTS stations using a drop camera and collection of
sediment samples at 31 stations using a Shipek grab.
The Flinders CMR survey was a pilot study undertaken in 2012 as part of the National Marine Biodiversity Hub's National Monitoring
Evaluation and Reporting Theme. The aim of this theme is to develop a blueprint for the sustained monitoring of the South-east
Commonwealth Marine Reserve Network, specifically; 1) to contribute to an inventory of demersal and epibenthic conservation
values in the reserve and 2) to test methodologies and deployment strategies in order to inform future survey design efforts.
Several gear types were deployed; including multibeam sonar, shallow-water (less than 150m) Baited Remote Underwater Video
Systems (BRUVS), deep- water BRUVS (to 600 m), towed video and digital stereo stills.
Embargo statement: Resource embargoed pending completion of NERP research. Release date 31 December 2014.
Attribution statement: Data was sourced from the NERP Marine Biodiversity Hub. The Marine Biodiversity Hub is supported through
funding from the Australian Government's National Environmental Research Program (NERP), administered by the Department of
Sustainability, Environment, Water, Population and Communities (DSEWPAC).
Dataset name: National Environmental Research Program (NERP) Marine Biodiversity Hub, 2012, Flinders Commonwealth Marine Reserve
Shelf Backscatter

Date (publication)

Product Type

Topic Category

Keywords

Resource Language

Resource Character Set

utf8

Resource Security Classification

unclassified

Geographic Extent

North bound

-40.4

East bound

148.85

West bound

148.55

South bound

-40.85

TEMPORAL EXTENT

2011-05-01 / 2012-08-01

Lineage

The backscatter data were processed using CMST-GA MB Process v12.05.07 software. The fully processed backscatter strengths
were corrected for transmission loss and insonification area. The process within the toolbox also involved removal of the
system transmission loss, removal of the system model, calculation of the incidence angle and removal of the angular dependence.
The grid values are basically the average values of the processed backscatter point data within each grid cell of predefined
size, normalised to the backscatter strength at an angle of 25 degrees.